At the least, I think everyone would be thoroughly disgusted. Doing something like that would be disrespectful to all those who died because of that madman. I don't know what I'd do if I saw someone doing that on the street. But I know what I'd be tempted to do: beat the everloving hell out of him.
There's just some things you don't joke about. People are just now able to accept Abraham Lincoln jokes. "I need to go to a theatre like I need a hole in the head." ... I love The Office.